Package: scindex 0.1.0

scindex: Strategic Convergence Index for Inter-Rater Reliability

Inter-rater reliability analysis for binary classification tasks involving two or more raters within a signal detection-theoretic framework. User-supplied rating data are standardised into a common long-format structure. The package automatically computes Cohen's kappa for two raters and Fleiss' kappa for multiple raters. When ground-truth labels are available, rater-specific hit rates, false-alarm rates, sensitivity, specificity, and decision thresholds are estimated from observed classification responses using standard signal detection-theoretic transformations (DeCarlo, 1998) <doi:10.1037/1082-989X.3.2.186>. The package implements the Strategic Convergence Index (SCI; Gianeselli, 2026) <doi:10.1177/00131644261417643>, defined as SCI = 1 - [Var(t_i) / Var_max], where Var(t_i) denotes the variance of rater-specific decision thresholds and Var_max denotes the reference variance under maximal threshold dispersion. SCI quantifies convergence in rater decision criteria beyond observed agreement alone and complements classical agreement coefficients by distinguishing agreement in observed categorical outcomes from convergence in latent decision thresholds under an explicit signal detection-theoretic model of categorical judgment. The package provides structured summaries and threshold-based diagnostics for applications in which similar agreement coefficients may reflect substantively different underlying decision criteria across raters.

Authors:Irene Gianeselli [aut, cre]